scholarly journals Litter Quality Is a Stronger Driver than Temperature of Early Microbial Decomposition in Oligotrophic Streams: a Microcosm Study

2021 ◽  
Author(s):  
Javier Pérez ◽  
Verónica Ferreira ◽  
Manuel A. S. Graça ◽  
Luz Boyero
Keyword(s):  
Water Temperature ◽  
Litter Decomposition ◽  
Atmospheric Carbon Dioxide ◽  
Litter Quality ◽  
Aquatic Hyphomycetes ◽  
Microbial Decomposition ◽  
Microcosm Study ◽  
Stream Functioning ◽  
Two Factors ◽  
Sporulation Rate

AbstractLitter decomposition is an ecological process of key importance for forest headwater stream functioning, with repercussions for the global carbon cycle. The process is directly and indirectly mediated by microbial decomposers, mostly aquatic hyphomycetes, and influenced by environmental and biological factors such as water temperature and litter quality. These two factors are forecasted to change globally within the next few decades, in ways that may have contrasting effects on microbial-induced litter decomposition: while warming is expected to enhance microbial performance, the reduction in litter quality due to increased atmospheric carbon dioxide and community composition alteration may have the opposite outcome. We explored this issue through a microcosm experiment focused on early microbial-mediated litter decomposition under stream oligotrophic conditions, by simultaneously manipulating water temperature (10 °C and 15 °C) and litter quality (12 broadleaf plant species classified into 4 categories based on initial concentrations of nitrogen and tannins). We assessed potential changes in microbial-mediated litter decomposition and the performance of fungal decomposers (i.e., microbial respiration, biomass accrual, and sporulation rate) and species richness. We found stronger effects of litter quality, which enhanced the performance of microbial decomposers and decomposition rates, than temperature, which barely influenced any of the studied variables. Our results suggest that poorer litter quality associated with global change will have a major repercussion on stream ecosystem functioning.

Fungal richness does not buffer the effects of streams salinization on litter decomposition

2021 ◽  
Vol 57 ◽  
pp. 5
Author(s):  
Janine Pereira da Silva ◽  
Aingeru Martínez ◽  
Ana Lúcia Gonçalves ◽  
Felix Bärlocher ◽  
Cristina Canhoto
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Fungal Biomass ◽  
Fungal Species ◽  
Aquatic Hyphomycetes ◽  
Negative Effects ◽  
Stream Functioning ◽  
Induced Changes ◽  
Sporulation Rate ◽  
The Impact

Freshwater salinization is a world-wide phenomenon threatening stream communities and ecosystem functioning. In these systems, litter decomposition is a main ecosystem-level process where fungi (aquatic hyphomycetes) play a central role linking basal resource and higher levels of food-web. The current study evaluated the impact of aquatic hyphomycete richness on leaf litter decomposition when subjected to salinization. In a microcosm study, we analysed leaf mass loss, fungal biomass, respiration and sporulation rate by fungal assemblages at three levels of species richness (1, 4, 8 species) and three levels of salinity (0, 8, 16 g NaCl L‑1). Mass loss and sporulation rate were depressed at 8 and 16 g NaCl L‑1, while fungal biomass and respiration were only negatively affected at 16 g L‑1. A richness effect was only observed on sporulation rates, with the maximum values found in assemblages of 4 species. In all cases, the negative effects of high levels of salinization on the four tested variables superimposed the potential buffer capacity of fungal richness. The study suggests functional redundancy among the fungal species even at elevated salt stress conditions which may guarantee stream functioning at extreme levels of salinity. Nonetheless, it also points to the possible importance of salt induced changes on fungal diversity and identity in salinized streams able to induce bottom-up effects in the food webs.

scholarly journals Can water temperature impact litter decomposition under pollution of copper and zinc mixture

2018 ◽  
Vol 16 (1) ◽  
pp. 473-480
Author(s):  
Gaozhong Pu ◽  
Xingjun Tian
Keyword(s):  
Water Temperature ◽  
Litter Decomposition ◽  
Enzyme Activities ◽  
Extracellular Enzyme ◽  
Plant Litter ◽  
Microbial Decomposition ◽  
Litter Mass ◽  
Mass Losses ◽  
The Impact ◽  
Cu And Zn

AbstractTo better understand the impact of warming on heavy metals (HM) associated with plant litter decomposition in streams, we investigated the impact of high and low HM (Cu and Zn) levels and different water temperatures (10,15 and 20oC) on microbial decomposition of TyphaangustifoliaL.litter and the associated extracellular enzyme activities. During a 100-day incubation, changes in litter mass losses, chemical composition (lignin and total carbohydrate), and extracellular enzyme activity were determined. The decomposition rates were accelerated by the low HM levels at 20oC (0.0051 day–1 at CK vs 0.0061 day–1 at low HM levels). The negative effects of Cu and Zn on Typha litter decomposition were more pronounced at lower temperatures (10 and 15°C). The enhanced enzyme activities of cellulase and β-glucosidase and the higher lignin/litter weight loss and lignin/carbohydrate ratios were found at 20oC and low HM treatment. The enzyme activities of β-glucosidase and cellulase were positively correlated with litter mass losses at 20oC and low HM levels. These results suggest that a 5oC increase in water temperature may attenuate the inhibition of low HM level on litter decomposition.

scholarly journals Combined effects of water temperature, grazing snails and terrestrial herbivores on leaf decomposition in urban streams

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7580 ◽  
Author(s):  
Hongyong Xiang ◽  
Yixin Zhang ◽  
David Atkinson ◽  
Raju Sekar
Keyword(s):  
Organic Matter ◽  
Water Temperature ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Decomposition Rate ◽  
Litter Quality ◽  
Urban Streams ◽  
Combined Effects ◽  
Decomposition Rates ◽  
Terrestrial Insects

The decomposition of organic matter in freshwaters, such as leaf litter, can affect global nutrient (e.g., carbon) cycling. This process can be influenced by fast urbanization through increased water temperature, reduced aquatic diversity and changed leaf litter quality traits. In this study, we performed a mesocosm experiment to explore the individual and combined effects of warming (8°C higher and ambient), the presence versus absence of grazing snails (Parafossarulus striatulus), and intraspecific difference of leaf litter quality (intact versus > 40% area of Liriodendron chinense leaves grazed by terrestrial insects) on litter decomposition in urban streams. Litter decomposition rates ranged from 0.019 d−1 to 0.058 d−1 with an average decomposition rate of 0.032 ± 0.002 d−1. All the three factors had significant effects on litter decomposition rate. Warming and the presence of snails accelerated litter decomposition rates by 60% and 35% respectively. Litter decomposition rates of leaves damaged by terrestrial insects were 5% slower than that of intact leaves, because litter quality of terrestrial insect-damaged leaves was lower (i.e., higher specific leaf weight) than intact leaves. For treatments with snails, warming stimulated microbial and snail mediated litter decomposition rates by 35% and 167%, respectively. All combinations of treatments showed additive effects on litter decomposition except for the interaction between warming and snails which showed positive synergistic effects. In addition, neither temperature nor litter quality affected snail growth rate. These results imply that higher water temperature and the presence of abundant snails in urban streams greatly enhanced litter decomposition. Moreover, the effect of pest outbreaks, which resulted in lower litter quality, can cascade to aquatic ecosystems by retarding microbe-mediated litter decomposition. When these factors co-occurred, warming could synergistically interact with snails to speed up the depletion of organic matter, while the effect of leaf quality on litter decomposition may be diminished at high water temperature. These effects could further influence stream food webs and nutrient cycling.

Ungulates decelerate litter decomposition by altering litter quality above and below ground

2016 ◽  
Vol 135 (5) ◽  
pp. 849-856 ◽  
Author(s):  
Michiru Kasahara ◽  
Saori Fujii ◽  
Toko Tanikawa ◽  
Akira S. Mori
Keyword(s):  
Litter Decomposition ◽  
Litter Quality ◽  
Below Ground

scholarly journals Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes

2013 ◽  
Vol 16 (8) ◽  
pp. 1045-1053 ◽  
Author(s):  
Pablo García-Palacios ◽  
Fernando T. Maestre ◽  
Jens Kattge ◽  
Diana H. Wall
Keyword(s):  
Litter Decomposition ◽  
Litter Quality ◽  
Soil Fauna

scholarly journals Invasive N-fixer Impacts on Litter Decomposition Driven by Changes to Soil Properties Not Litter Quality

Ecosystems ◽  
2017 ◽  
Vol 20 (6) ◽  
pp. 1151-1163 ◽  
Author(s):  
Arthur A. D. Broadbent ◽  
Kate H. Orwin ◽  
Duane A. Peltzer ◽  
Ian A. Dickie ◽  
Norman W. H. Mason ◽  
...  
Keyword(s):  
Soil Properties ◽  
Litter Decomposition ◽  
Litter Quality

Long-term responses of leaf litter decomposition to temperature, litter quality and litter mixing in plateau wetlands

2016 ◽  
Vol 62 (1) ◽  
pp. 178-190 ◽  
Author(s):  
Guodong Liu ◽  
Jinfang Sun ◽  
Kun Tian ◽  
Derong Xiao ◽  
Xingzhong Yuan
Keyword(s):  
Leaf Litter ◽  
Litter Decomposition ◽  
Litter Quality ◽  
Leaf Litter Decomposition ◽  
Litter Mixing ◽  
Plateau Wetlands

Seasonal occurrence of Conidia of Aquatic Hyphomycetes (Fungi) in Lees Creek, Australian Capital Territory

1989 ◽  
Vol 40 (1) ◽  
pp. 11 ◽  
Author(s):  
K Thomas ◽  
GA Chilvers ◽  
RH Norris
Keyword(s):  
Water Temperature ◽  
Northern Hemisphere ◽  
Membrane Filtration ◽  
Linear Regression Analysis ◽  
Late Summer ◽  
Multiple Linear Regression Analysis ◽  
Aquatic Hyphomycetes ◽  
Individual Species ◽  
Minimum Concentration ◽  
Summer Minimum

The aquatic hyphomycete spora of an upland stream (Lees Creek) were sampled twice monthly by membrane filtration at two sites, the upstream one with native riparian vegetation and the downstream one with exotic pines. Physicochemical properties of the water were measured at each sampling. Conidia of 43 species were collected, of which 18 are undescribed and most species occurred at both sites. The peak concentrations of conidia occurred in late summer to early autumn and minimum concentration in winter. This contrasts with the autumn-winter maximum and summer minimum concentrations recorded for tree-lined streams of the Northern Hemisphere. These differences correspond with differences in seasonality of litter fall in the Northern Hemisphere compared with Australia. Analysis of variance showed significant differences between the two sites for concentrations of conidia of individual species and of total conidia. The magnitude of these differences was related to the time of sampling. Using multiple linear regression analysis, the occurrences of conidia detected at the up-stream site were best explained by water temperature; down-stream, rainfall and water temperature together explained most variance.

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